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<h1>Master file table (MFT)</h1>

<p>Every element in the NTFS file system is a file, even its service data. The most important NTFS file is referred to as the Master (or main) File Table (MFT). It is located in MFT area acting as a centralized directory for all files of a drive, including itself. The MFT zone is created during formatting of a logical drive; by default, it occupies 12,5 % of volume capacity (depending upon the NtfsMftZoneReservation parameter value it can take 25%, 37% or 50%).</p>

<p>This area is the location of the $MFT file, which initially takes approximately 64&nbsp;sectors and grows from the MFT zone start to its end as new user files/subdirectories are created. The approximate size of the MFT file can be evaluated as a product of table record element (usually 1&nbsp;Kb) and the total number of partition files/subdirectories including the ones deleted recently.</p>

<p>To prevent fragmentation of the $MFT file, the MFT zone remains reserved until all free space on the volume is used up, then the unused "tail" of the MFT zone will be divided in two leaving space for user files. The process can be repeated several times until the reserved space is reclaimed completely. </p>

<p>When necessary, $MFT file can be relocated to any disk part, then it will be outside the volume beginning. The initial address of the $MFT file is stored in boot sector at offset 30h bytes from its beginning.</p>

<h6><img src="Master%20file%20table%20%28MFT%29_files/mft_0100.gif"></h6>

<h6>NTFS drive volume structure</h6>

<p>$MFT file is a collection of entries of the FILE&nbsp;Record type. Each such record describes a corresponding file or subdirectory. In most cases, a single file/subdirectory is described completely by one FILE&nbsp;Record, although theoretically it may require several records.<br>
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